System and method for polymer distribution to well sites

ABSTRACT

The invention relates to a polymer transport and distribution system comprising a vessel, pipeline or network of pipes containing polymer mother solution, and one or more pumps for transporting polymer mother solution from a first location to one or more injection well sites at a second remote location, each injection well comprising a polymer mother solution input feed line, a water input feed line, and a second pump for controlling mother solution flow rate and pressure upstream from the water input feed line, for producing polymer daughter solution from polymer mother solution and water, and injecting the resulting polymer daughter solution into an oil or gas field well. Also provided are methods of distributing polymer to one or more injection well sites in an oil or gas field.

FIELD OF INVENTION

The present invention relates to oil and gas recovery. Morespecifically, the present invention relates to polymer use in oil andgas recovery.

BACKGROUND OF THE INVENTION

Polymer compounds are used in the oil industry to prevent fingering insubterranean oil formations. In most cases, polymer solutions areprepared at each well site and the resulting formulation is injectedinto a well. As most oil fields comprise several injector-producerwells, there is often a need to inject polymer into several wells withinthe field. Typically, at each injection well, dry polymer powder ismixed with an appropriate quantity of water and the resulting solutionis injected into the well. This approach requires dry polymer to betransported to the various well sites. Further, mixing systems, polymerholding tanks and the like must be stationed at each well site wherepolymer is injected. This requires transportation systems such as roadsand other types of costly infrastructure to be implemented to ensurethat the proper components and products are present at the appropriatelocations and at the appropriate times. Further, this type of approachmust be monitored closely to ensure a continuous supply of dry polymerfor injection and also to ensure the mechanical components required forinjection at each point are working properly.

There is a need in the art for novel polymer transportation anddistribution systems in oil and gas fields. Further, there is a need forsystems and methods of preparing polymer at a central location andtransporting the same, potentially over large distances to several wellsites where the polymer may be diluted if necessary to a desiredviscosity and pumped down-well.

SUMMARY OF THE INVENTION

The present invention relates to oil and gas recovery. Morespecifically, the present invention relates to polymer use in oil andgas recovery.

According to the present invention, there is provided a polymertransport and distribution system comprising,

-   -   a vessel, pipeline or network of pipes containing polymer mother        solution, and;    -   one or more pumps for transporting polymer mother solution from        a first location to one or more injection well sites at a second        remote location, each injection well comprising a polymer mother        solution input feed line, a water input feed line, a second pump        for controlling mother solution flow rate and pressure, the        second pump upstream of the water input feed line, for producing        polymer daughter solution from polymer mother solution and        water, and injecting the resulting polymer daughter solution        into an oil or gas field well.

Also according to the present invention, there is provided a polymertransport and distribution system comprising,

-   -   a vessel, pipeline or network of pipes containing polymer mother        solution, and;    -   one or more pumps for transporting polymer mother solution from        a first location to one or more injection well sites at a second        remote location, each injection well comprising a polymer mother        solution input feed line, a high pressure dilution water input        feed line, and a second pump for controlling mother solution        flow rate and pressure, upstream of the high pressure dilution        water input feed line for producing polymer daughter solution        from polymer mother solution and water, and injecting the        resulting polymer daughter solution into an oil or gas field        well.

Also provided is a polymer transport and distribution system as definedabove, further comprising at least one mixer for mixing polymer mothersolution with water.

The present invention also contemplates a polymer transport anddistribution system as defined above, wherein the polymer comprisespolyacrylamide, hydrolysed polyacrylamide, xanthan gum, guar gum, diutangum, welan gum or a combination thereof.

Also provided is a polymer transport and distribution system as definedabove, wherein the polymer comprises a viscosity in the range of about 1to about 25000 cP.

The present invention further contemplates a polymer transport anddistribution system as defined above, wherein either the polymer mothersolution, the polymer daughter solution or both comprise less than about50000 ppm total dissolved solids. In an embodiment, which is not meantto be limiting, the polymer mother solution, polymer daughter solutionor both comprise less than about 25000 ppm, more preferably less thanabout 18000 ppm total dissolved solids. In a further embodiment, whichis not meant to be limiting, the polymer mother solution, polymerdaughter solution or both comprise less than 5000 ppm total dissolvedsolids.

Also provided by the present invention is a polymer transport anddistribution system as defined above, wherein the polymer mothersolution, polymer daughter solution or both comprise a surfactant,biocide, alkaline component, antifoaming agent, or a combinationthereof.

The present invention also contemplates a polymer transport anddistribution system as defined above, wherein the polymer daughtersolution comprises polymer mother solution diluted with water.

Also provided by the present invention is a polymer transport anddistribution system as defined above, wherein the water is derived froma saline well, a freshwater well, a water filtration skid or acombination thereof.

The present invention also contemplates a polymer transport anddistribution system further comprising one or more of:

-   -   a) a dry polymer holding vessel;    -   b) a dry polymer transfer system;    -   c) a water inlet source for hydrating dry polymer;    -   d) an input source for adding one or more additional components        to the dry polymer, water or polymer mother solution,    -   e) a mixer for preparing polymer mother solution, and;    -   g) a polymer mother solution holding vessel.

Also provided by the present invention is a polymer transport anddistribution system as defined above that comprises a dry polymerpolymer transfer system, wherein the system comprises a calibrated augeror a helix conveyor. Also, the system may further comprise a mixer.

The present invention also contemplates a polymer transport anddistribution system comprising,

-   -   a dry polymer transfer system, a water inlet source, and a first        mixer for preparing a polymer mother solution from said dry        polymer and water,    -   one or more pumps for transporting polymer mother solution        through a pipeline or network of pipes to one or more remote        injection pod sites, each injection pod site comprising,    -   one or more injection wells, each injection well comprising a        polymer mother solution input feed line, one or more pumps for        controlling mother solution flow rate and pressure upstream of a        water input feed line, preferably a high pressure dilution water        input feed line, to produce polymer daughter solution for        injection into a well.

The present invention also provides a method of distributing polymer toone or more injection well sites in an oil or gas field comprising,

-   -   a) providing a polymer mother solution;    -   b) pumping the polymer mother solution through a pipeline or        network of pipes from a first location to one or more remote        locations comprising at least one injection pod or well site;    -   c) mixing the polymer mother solution with water and optionally        one or more additional components to form a polymer daughter        solution and;    -   d) injecting the polymer daughter solution into a well.

The present invention also provides a method of distributing polymer toone or more injection well sites in an oil or gas field comprising,

-   -   a) storing or producing a polymer mother solution in a polymer        processing station;    -   b) pumping the polymer mother solution through a pipeline or        network of pipes from the polymer processing station to one or        more remote injection pods or injection well sites;    -   c) mixing the polymer mother solution with water and optionally        one or more additional components at the injection pod or        injection well contained therein to form a primary polymer        daughter solution and;    -   d) injecting the primary polymer daughter solution into the        injection well;    -   e) extracting oil or gas from a producer well in fluid        communication with the injection well, and;    -   f) optionally, mixing polymer mother solution with water and if        desired, one or more additional components at the injection pod        or injection well site contained therein to form a secondary        polymer daughter solution, wherein the secondary polymer        daughter solution is more dilute in polymer concentration and        less viscous than the primary daughter solution,    -   g) injecting the secondary daughter polymer solution into the        injection well;    -   h) extracting oil from the producer well in fluid communication        with the injection well, and;    -   i) optionally repeating steps f)-h) using successively more        dilute and less viscous daughter solutions.

This summary of the invention does not necessarily describe all featuresof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the invention will become more apparent fromthe following description in which reference is made to the appendeddrawings wherein:

FIG. 1 shows a representative embodiment of a polymer transport anddistribution system according to the present invention.

DETAILED DESCRIPTION

The following description is of a preferred embodiment.

The present invention will be further illustrated in the followingexamples.

According to an embodiment of the present invention, there is provided apolymer transport and distribution system comprising,

-   -   a vessel, pipeline or network of pipes containing polymer mother        solution;    -   one or more pumps for transporting polymer mother solution from        a first location to one or more injection well sites at a second        remote location, each injection well comprising a polymer mother        solution input feed line, a water input feed line, and a second        pump for controlling mother solution flow rate and pressure,        preferably at or upstream of the water input feed line, for        producing polymer daughter solution from polymer mother solution        and water, and injecting the resulting polymer daughter solution        into an oil or gas field well.        In a preferred embodiment, the water input feed line is a high        pressure dilution input feed line.

In a preferred embodiment, which is not meant to be limiting in anymanner, there is provided a polymer transport and distribution systemcomprising,

-   -   a vessel containing a polymer mother solution;    -   one or more pumps for transporting polymer mother solution from        the vessel through a pipeline or network of pipes to one or more        injection pod sites, each injection pod site comprising,    -   a second pump for controlling mother solution flow rate and        pressure upstream of a high pressure dilution water input feed        line used to produce polymer daughter solution from polymer        mother solution and water, the water optionally derived from a        vessel, pipeline or network of pipes carrying water, and        injecting the resulting polymer daughter solution into an oil or        gas field well.

It is to be understood that the polymer transport and distributionsystem may further comprise a mixer that mixes the polymer mothersolution with water to produce polymer daughter solution. Inclusion of amixer is optional as the combination of polymer mother solution withwater to make polymer daughter solution and the subsequent injecting ofthe polymer daughter solution into an oil and gas field well is usuallysufficient to ensure thorough mixing. However, there are instanceswhereby it may be desirable to include a mixer, for example, but notlimited to, when the viscosity of the polymer mother solution is highcompared to that of water or in instances when the polymer mothersolution is diluted by either a very small or very large amount. Aperson of skill in the art would be able to determine if a mixer shouldbe included in the polymer transport and distribution system havingregard to the information provided herein.

By the term “polymer mother solution” it is meant an aqueous solutioncomprising a polymer, water and optionally one or more additionalcomponents. The polymer may comprise any polymer known in the art, forexample, but not limited to polyacrylamide including, but not limited tohydrolyzed polyacrylamide, xanthan gum, guar gum, diutan gum, welan gumor a combination thereof. In an embodiment of the present invention,which is not meant to be limiting in any manner, the polymer mothersolution comprises a polyacrylamide polymer. In an alternate embodiment,the polymer mother solution comprises xanthan gum. In still a furtherembodiment, which is not meant to be limiting, the polymer mothersolution comprises guar gum. However, it is to be understood that othertypes of polymers, biopolymers, viscosifying agents or any combinationthereof may be employed in the present invention. Accordingly, the listof polymers provided above is not meant to be limiting in any manner.

The polymer mother solution preferably has a viscosity in the range ofabout 1 to about 25000 cP, more preferably about 5 to 15000 cP and stillmore preferably about 10 to about 10000 cP. For example, the polymermother solution may comprise a viscosity of about 1, 5, 10, 50, 100,500, 1000, 2000, 5000, 10000, 15000, 20000, 25000 cP or any amounttherein between. Further, the viscosity of the polymer mother solutionmay be defined by a range of any two of the values provided above or anyamounts therein between. However, a polymer mother solution comprisingcharacteristics outside one or more of these ranges is alsocontemplated.

The viscosity of polymer mother solution may be measured according toknown methods in the art, and any such method may be employed todetermine the viscosity of the polymer solutions as defined herein. Forexample, but not to be considered limiting in any manner, viscosity maybe measured in accordance with the American Petroleum Institute (API)Recommended Practice 63 (RP63), First Edition, Jun. 1, 1990, which ishereby incorporated by reference.

In embodiments wherein the polymer mother solution comprisespolyacrylamide polymer, it is preferred that the solution does notcomprise water with high levels of total dissolved solids, particularlycationic or divalent species as these components can inhibit hydrolysisof polymer and/or breakdown the viscosity of such polymer solutions. Inembodiments wherein polyacrylamide polymer is employed in the polymertransport and distribution system, preferably the total dissolved solidsis less than about 5000 ppm, more preferably less than 2000 ppm.

By the term “total dissolved solids” it is meant the sum of anions andcations from water analysis. Cations may be determined by InductivelyCoupled Plasma (ICP) using American Public Health Association (APHA)3120 method. Chloride may be determined by titration (APHA 4500-C1:B),sulfate by APHA 3120 and alkalinity by titration according to APHA2320:B. Alternatively, other methods to measure total dissolved solidsas would be known to a person of skill in the art may be employed.

As xanthan gum polymers exhibit increased resistance to viscositybreakdown in the presence of salts, the use of such polymers ispreferred in instances wherein the polymer is mixed with water thatcomprises a high content of total dissolved solids, salts, iron,iron-containing species, or a combination thereof. In a preferredembodiment, which is not meant to be limiting in any manner, xanthan gumpolymers are employed in polymer compositions wherein the content oftotal dissolved solids (excluding polymer) is greater than about 2000ppm.

As described previously, it is also contemplated that the polymer mothersolution may comprise one or more additional components, for example,but not limited to a surfactant, biocide, alkaline component such as,but not limited to caustic soda, antifoaming agent, or a combinationthereof. In the event that a surfactant or other component is employedin the polymer mother solution, it preferably comprises an amountbetween about 20 parts per million (ppm) and about 5000 ppm, preferablyabout 500 ppm and about 5000 ppm, for example, but not limited to 20,50, 100, 200, 500, 1000, 2000, 2500, 3000, 4000, 5000 or any amounttherein between. Further, the surfactant may be defined by a range ofany two of the values listed above or any amount therein between.Without wishing to be bound by theory or limiting in any manner, asurfactant may lower the interfacial tension of oil deposits andfacilitate extraction from subterranean formations.

By the term “polymer daughter solution” it is meant an aqueous solutioncomprising the polymer mother solution, water and optionally one or moreadditional components. Typically, the polymer daughter solutioncomprises a polymer concentration that is about the same or less thanthe polymer mother solution. As such, the polymer daughter solutionusually comprises a lower viscosity than the polymer mother solution.

It is also to be understood that the polymer daughter solution maycomprise one or more additional components not found in the polymermother solution. Similarly, the polymer daughter solution may compriseone or more additional components in a different concentration ascompared to the polymer mother solution. By way of example, but not tobe considered limiting in any manner, the polymer mother solution may beprepared using a potable water source having low salinity. Prior tobeing injected into a well, the polymer mother solution may be dilutedwith water from a saline well having high salinity. Accordingly, it isapparent that the polymer daughter solution may comprise higher levelsof dissolved salts, and potentially other components as compared to thepolymer mother solution. In still a further embodiment, which is notmeant to be considered limiting in any manner, the polymer daughtersolution may comprise an added surfactant not present in the polymermother solution. Other potential differences between the polymer mothersolution and the polymer daughter solution will be evident to a personof skill in the art having regard to the disclosure as provided herein.

In an embodiment which is not meant to be limiting in any manner, thepolymer daughter solution is polymer mother solution diluted with water.In a specific embodiment, but not wishing to be considered limiting inany manner, the polymer daughter solution comprises polyacrylamidesolution of between about 500 ppm and about 2000 ppm, more preferablyabout 1000 to about 1500 ppm. However, a polymer daughter solutionoutside this range is also contemplated.

In the embodiments described herein, it is preferred that polymer mothersolution is sufficiently hydrolysed prior to being diluted to formpolymer daughter solution and before injection into a well. For example,but not wishing to be limiting, the polymer mother solution may remainin a vessel, holding tank, pipeline or network of pipes for at least aspecified duration in order for the polymer to hydrolyse to a desiredviscosity. Further, it is contemplated that the extent of hydrolysisand/or the viscosity of the solution may be measured and/or monitored atone or more points within the polymer transport system including forexample, but not limited to the vessel, holding tank, pipeline, networkof pipes, or injection pod polymer mother solution feed line by anymethod known in the art. Without wishing to be limiting or bound bytheory in any manner, it is possible that some polymers may require timeto fully hydrate, unravel and expand to create a viscous solution.

The polymer mother solution may be provided as a premade solution oralternatively, the polymer mother solution may be prepared on site, forexample, but not limited to, by mixing together dry polymer, water andoptionally one or more additional components. Accordingly, the polymertransport and distribution system may comprise a dry polymer holdingvessel or container, a dry polymer transfer system, a water inletsource, an input source for optionally adding one or more additionalcomponents to the dry polymer, water or polymer mother solution, a mixerfor preparing the polymer mother solution, a polymer mother solutiontransport system, for example, but not limited to one or more pumps, avessel or container for holding polymer mother solution, one or morepipelines or network of pipes or any combination thereof. Several or allof these components may be contained in a polymer processing station(polymer pod) which may be or may not be located remotely from theinjection pod sites and wells.

The water inlet source providing water for mixing with polymer may beprovided from a well, for example, but not limited to a freshwater orsaline well, water pipeline, water filtration skid or the like. It isalso contemplated that the water inlet source may be connected to awater pipeline or network of water pipes that extends over the oil/gasfield being tapped. In an embodiment, the water is substantially puremeaning that it comprises a low amount, for example between 1500 toabout 2500 ppm, or lower of total dissolved solids as described herein,particularly salts as high levels of salts and are known to inhibithydrolysis and/or promote breakdown of hydrolysed polymers such aspolyacrylamides. However, water from a saline well also may be employed,and may be preferred in instances wherein the polymer is resistant toviscosity breakdown in the presence of dissolved salts.

Dry polymer may be fed into a mixer by a dry polymer transfer systemwhich may comprise without limitation, a calibrated auger or the like.In a preferred embodiment, the dry polymer transfer system comprises aHapman helix conveyor. Alternatively, the dry polymer may be transferredby an air transfer system or both an air transfer system and a conveyor.Any such system as would be known in the art may be employed in thepolymer transport and distribution system. Further, one or more optionalcomponents may be added likewise or they may be added using othermethods and/or apparatuses known in the art.

The mixing of dry polymer, water and optionally any additionalcomponents may be performed in any vessel, holding tank or pipeline by asuitable mixer or mixing device. In a preferred embodiment, the mixer ormixing device is a Model 1700 Comitrol Processor made by Urschel Labs.Such a device has been shown to decrease the time necessary to prepareviscous polymer mother solution. While such devices are preferred, othermixing devices can be employed in the present invention. As will beevident to a person of skill in the art, it is preferred that polymerpowder is thoroughly mixed with water and attains the desired viscosityprior to being diluted to form polymer daughter solution or injectedinto a well. In this manner, polymer mother solution may be prepared andretained in a vessel or holding tank until the polymer mother solutionexhibits a desired viscosity. Alternatively, polymer mother solution maybe prepared and transported in a pipeline or network of pipes to asecond remote location. In such an embodiment, it is preferred that thepolymer mother solution attain the desired viscosity while being pumpedthrough the pipeline or network of pipes before being diluted to formpolymer daughter solution or injected into a well.

The embodiment described above contemplates that that the vesselcontaining the polymer mother solution or the polymer processing stationthat prepares the polymer mother solution can be located remotely fromthe injection pod or well sites, for example, but not limited to about1, 2, 5, 6, 10 or more km therefrom. Thus, polymer mother solution maybe prepared and/or stored in a separate area, building, or facility fromthat of the injection pods wherein the daughter polymer solution isinjected into a well. Polymer mother solution can be pumped from thisremote site through a pipeline or network of pipes to the injection podsites wherein the polymer mother solution is diluted with water andoptionally formulated with other components to obtain a daughter polymersolution having a desired viscosity and/or one or more desired chemicalcharacteristics for injection into a well. Further, but without wishingto be limiting in any manner, the water used for mixing with polymermother solution may be provided via a vessel, pipeline or network ofpipes that parallels or intersects that providing the polymer mothersolution at one or more points. In an embodiment of the presentinvention, the polymer transport and distribution system comprises aplurality of injection pod sites, for example, two, three, four, five ormore injection pod sites. In a preferred embodiment, the polymertransport and distribution system comprises five or less sites.Similarly, in an embodiment of the present invention, the polymertransport and distribution system comprises a plurality of injectionwells within each injection pod site, for example two, three, four ormore injection wells. In a preferred embodiment the polymer distributionand transport system comprises four injection wells within eachinjection pod site.

Referring now to FIG. 1, there is shown a representative non-limitingembodiment of the present invention. Polymer processing station (polymerpod (10)) receives water from a freshwater source (20) to producepolymer mother solution which is pumped through polymer mother solutionpipeline network (30) to a plurality of injection pods or injection wellsites (40). Each injection well site (40) comprises a polymer mothersolution feed line (50), a water input feed line (60) providing highpressure dilution water from water pipeline network (35) and at least asecond pump for controlling mother solution flow rate and pressureupstream of the water input feed line used for producing and injectingpolymer daughter solution into an oil or gas field well (70). Also shownare producer wells (80) for extracting oil and gas from subterraneanformations in an oil or gas field (100).

In an alternate embodiment of the present invention which is not meantto be limiting in any manner, the polymer transport and distributionsystem comprises,

-   -   a dry polymer transfer system, a water inlet source, and a first        mixer for preparing a polymer mother solution from dry polymer        and water, the resulting polymer mother solution contained in a        vessel;    -   one or more pumps for transporting polymer mother solution        through a pipeline or network of pipes to one or more remote        injection pod sites, each injection pod site comprising,    -   one or more injection wells, each injection well comprising a        polymer mother solution input feed line, a high pressure water        input feed line, a second mixer to produce polymer daughter        solution and a pump for controlling mother solution flow rate        and pressure upstream of a high pressure dilution water input        feed line, for injecting the resulting polymer daughter solution        into a well.

The present invention also provides a method of distributing polymer toone or more injection well sites in an oil or gas field comprising,

-   -   a) providing a polymer mother solution;    -   b) pumping the polymer mother solution through a pipeline or        network of pipes from a first location to one or more remote        locations comprising at least one injection pod or well site;    -   c) mixing the polymer mother solution with water and optionally        one or more additional components to form a polymer daughter        solution and;    -   d) injecting the polymer daughter solution into a well.

In a further embodiment of the present invention there is provided amethod of distributing polymer to one or more injection well sites in anoil or gas field comprising,

-   -   a) storing or producing a polymer mother solution in a polymer        processing station;    -   b) pumping the polymer mother solution through a pipeline or        network of pipes from the polymer processing station to one or        more remote injection pod or well sites;    -   c) mixing the polymer mother solution with water and optionally        one or more additional components to form a polymer daughter        solution and;    -   d) injecting the polymer daughter solution into a well.

In an alternate embodiment of the present invention, there is provided amethod of distributing polymer to one or more injection well sites in anoil or gas field comprising,

-   -   a) storing or producing a polymer mother solution in a polymer        processing station;    -   b) pumping the polymer mother solution through a pipeline or        network of pipes from the polymer processing station to one or        more remote injection pods or injection well sites;    -   c) mixing the polymer mother solution with water and optionally        one or more additional components at the injection pod or        injection well contained therein to form a primary polymer        daughter solution and;    -   d) injecting the primary polymer daughter solution into the        injection well;    -   e) extracting oil from a producer well in fluid communication        with the injection well, and;    -   f) optionally, mixing polymer mother solution with water and if        desired, one or more additional components at the injection pod        or injection well site contained therein to form a secondary        polymer daughter solution, wherein the secondary polymer        daughter solution is more dilute in polymer concentration and        less viscous than the primary daughter solution,    -   g) injecting the secondary daughter polymer solution into the        injection well;    -   h) extracting oil from the producer well in fluid communication        with the injection well, and;    -   i) optionally repeating steps f)-h) using successively more        dilute and less viscous daughter solutions.

EXAMPLES

In a preferred embodiment of the present invention, polymer is broughtonto a skid in 750 kg bags via an overhead crane. The bags of drypolymer are hoisted over top and unloaded into a hopper. From thehopper, the polymer is transferred, for example via a Hapman helixconveyor/auger to a storage silo. From storage silo, polymer powder isaugured into a mixer, for example, but not limited to an Urschel mixeror the like. Water is filtered through a standard bag filter and thenfed into the mixer at the same time in controlled proportions to createdthe required polymer mother solution. Typically, but not always, thepolymer mother solution comprises from about 5000 to 15000 ppm dependingon particular well injection requirements. The polymer mother solutionfalls out of the bottom of the urschel mixer and is then transferred toa tank via a lobe pump where it undergoes hydrolysis prior to beingdiluted to form polymer daughter solution.

Once the polymer mother solution has sufficiently hydrolysed, it ispumped through a pipeline or pipeline network to the injection pod orinjection well sites. This is accomplished by a progressive cavity pumpwhich draws the polymer off the bottom of the tank and pressurizes it upto the pressure required to transport the polymer to distant/remoteinjection pod or well sites. In this example, but not to be consideredlimiting in any manner, the pipeline feeds up to 5 injection pods whichare up to about 1.6 km away from the polymer processing station. Eachinjection pod comprises a separate pump for each well wherein polymer isinjected. The pod sites are laid out with 4 injection wells per pod.There is one injection skid per pod which has four pumps in it to feedthe wells. Polymer mother solution is metered as it goes out thebuilding, and then it is blended with water to create polymer daughtersolution having the required polymer concentration before being injecteddown the wells. Typical polymer concentrations of polymer daughtersolution injected down each well are about 1000 to about 1500 ppm thusrequiring roughly a 9:1 blend of water to polymer mother solution.

All citations are hereby incorporated by reference.

The present invention has been described with regard to one or moreembodiments. However, it will be apparent to persons skilled in the artthat a number of variations and modifications can be made withoutdeparting from the scope of the invention as defined in the claims.

1. A polymer transport and distribution system comprising, a vessel,pipeline or network of pipes containing polymer mother solution, and;one or more pumps for transporting polymer mother solution from a firstlocation to one or more injection well sites at a second remotelocation, each injection well comprising a polymer mother solution inputfeed line, a water input feed line, and a second pump for controllingmother solution flow rate and pressure upstream of the water input feedline, and for producing polymer daughter solution from polymer mothersolution and water, and injecting the resulting polymer daughtersolution into an oil or gas field well.
 2. The polymer transport anddistribution system of claim 1, further comprising at least one mixerfor mixing polymer mother solution with water.
 3. The polymer transportand distribution system of claim 1, wherein the polymer comprisespolyacrylamide, hydrolysed polyacrylamide, xanthan gum, guar gum, diutangum, welan gum or a combination thereof.
 4. The polymer transport anddistribution system of claim 3, wherein the polymer comprises aviscosity in the range of about 1 to about 25000 cP.
 5. The polymertransport and distribution system of claim 1, wherein either the polymermother solution, the polymer daughter solution or both comprise lessthan about 50000 ppm total dissolved solids.
 6. The polymer transportand distribution system of claim 1, wherein the polymer mother solution,polymer daughter solution or both comprise a surfactant, biocide,alkaline component, antifoaming agent, or a combination thereof.
 7. Thepolymer transport and distribution system of claim 1, wherein thepolymer daughter solution comprises polymer mother solution diluted withwater.
 8. The polymer transport and distribution system of claim 8,wherein said water is derived from a saline well, a freshwater well, awater filtration skid or a combination thereof.
 9. The polymer transportand distribution system of claim 1 further comprising one or more of: a)a dry polymer holding vessel; b) a dry polymer transfer system; c) awater inlet source for hydrating dry polymer; d) an input source foradding one or more additional components to the dry polymer, water orpolymer mother solution, e) a mixer for preparing polymer mothersolution, and; g) a polymer mother solution holding vessel.
 10. Thesystem of claim 9, comprising a dry polymer polymer transfer system,wherein said system comprises a calibrated auger or a helix conveyor.11. The system of claim 10, wherein the system comprises a mixer.
 12. Apolymer transport and distribution system comprising, a dry polymertransfer system, a water inlet source, and a first mixer for preparing apolymer mother solution from said dry polymer and water, one or morepumps for transporting polymer mother solution through a pipeline ornetwork of pipes to one or more remote injection pod sites, eachinjection pod site comprising, one or more injection wells, eachinjection well comprising a polymer mother solution input feed line anda water input feed line to produce polymer daughter solution, and a pumpfor controlling mother solution flow rate and pressure upstream of thewater input feed line, for injecting the resulting polymer daughtersolution into a well.
 13. A method of distributing polymer to one ormore injection well sites in an oil or gas field comprising, a)providing a polymer mother solution; b) pumping the polymer mothersolution through a pipeline or network of pipes from a first location toone or more remote locations comprising at least one injection pod orwell site; c) mixing the polymer mother solution with water andoptionally one or more additional components to form a polymer daughtersolution and; d) injecting the polymer daughter solution into a well.14. A method of distributing polymer to one or more injection well sitesin an oil or gas field comprising, a) storing or producing a polymermother solution in a polymer processing station; b) pumping the polymermother solution through a pipeline or network of pipes from the polymerprocessing station to one or more remote injection pods or injectionwell sites; c) mixing the polymer mother solution with water andoptionally one or more additional components at the injection pod orinjection well contained therein to form a primary polymer daughtersolution and; d) injecting the primary polymer daughter solution intothe injection well; e) extracting oil or gas from a producer well influid communication with the injection well, and; f) optionally, mixingpolymer mother solution with water and if desired, one or moreadditional components at the injection pod or injection well sitecontained therein to form a secondary polymer daughter solution, whereinthe secondary polymer daughter solution is more dilute in polymerconcentration and less viscous than the primary daughter solution, g)injecting the secondary daughter polymer solution into the injectionwell; h) extracting oil from the producer well in fluid communicationwith the injection well, and; i) optionally repeating steps f)-h) usingsuccessively more dilute and less viscous daughter solutions.